1. Field of the Invention
The present invention relates in general to electromagnetic valves used, for example, in a motor vehicle, and more particularly to a unit consisting of electromagnetic valves used for controlling an anti-lock braking system of the motor vehicle.
2. Description of the Prior Art
In order to clarify the task of the present invention, one conventional unit consisting of electromagnetic valves for such anti-lock braking system (viz., ABS) will be outlined with reference to FIG. 3 of the accompanying drawings, which is shown in Japanese Patent First Provisional Publication 63-96378.
In FIG. 3, there is shown a sectional and partial view of the conventional unit. Numeral 20 designates a valve housing, and numerals 21A and 21B designate electromagnetic valves which have valve proper portions 22 held by the valve housing 20. Numerals 23A and 23B designate respective coils possessed by the electromagnetic valves 21A and 21B, and numeral 24 designates liquid passages formed in the valve housing 20. Each coil 23A or 23B is tightly held in a bobbin 25A or 25B. As shown, each coil 23A or 23B and the associated bobbin 25A or 25B are surrounded by an outer wall 26. Mounted on a top of the outer wall 26 is a cover member 27 which tightly holds upper portions of the electromagnetic valves 21A and 21B. For the tight holding of the valves 21A and 21B, the cover member 27 is formed with openings 31 into which the upper portions of the valves 21A and 21B are fitted. The cover member 27 carries thereon a printed-circuit board 28. The printed circuit on the board 28 includes power lines and control lines for the electromagnetic valves 21A and 21B. Numerals 29 and 29 designate terminals from the coils 23A and 23B, which are connected via welding or the like to given portions of the printed circuit. Numeral 30 designates a housing cover which is mounted on the valve housing 20 to cover and protect the electromagnetic valves 21A and 21B and the printed-circuit board 28.
However, due to its inherent construction, the above-mentioned conventional unit has the following drawbacks.
That is, because the printed-circuit board 28 is positioned at an opposite side of the coils 23A and 23B with respect to the cover member 27, the cover member 27 has to have openings (not shown) through which the terminals 29 and 29 from the coils 23A and 23B pass toward the printed-circuit board 28. However, provision of such openings in the cover member 27 in addition to the openings 31 for the electromagnetic valves 1A and 1B not only lowers the mechanical strength of the cover member 27 but also induces a difficulty with which the cover member 27 is produced.